Phenolepoxy resins prepared from an aqueous-phase-free process

ABSTRACT

A number of new phenolepoxy resins are prepared by reacting polyphenol, epihalohydrin and imidazole in a homogeneous reaction medium. These include the following compounds: ##STR1##

This is a continuation-in-part of application Ser. No. 08/841,728, filedApr. 26, 1997 and now U.S. Pat. No. 5,844,062.

FIELD OF THE INVENTION

The present invention relates to a new family of epoxy resins. Morespecifically, the present invention relates to a family of novelphenolepoxy resins which are prepared from a greatly simplified, andthus more cost-effective, process but which exhibit the kind ofmechanical and adhesive properties that are at least as good as those ofother high-performance commercially available epoxy resins such as epoxycresol-novolac resins, etc. The phenolepoxy resins disclosed in thepresent invention are most advantageous for use in IC packaging,including encapsulation, in making printed circuit boards, and asadhesives in making electronic components, etc. The present inventionalso relates to the novel process for making the phenolepoxy resins.

BACKGROUND OF THE INVENTION

Epoxy resins are characterized by the presence of a three-memberedcyclic ether group commonly referred to as an epoxy group, 1,2-epoxide,or oxirane. The most widely used epoxy resins are diglycidyl ethers ofbisphenol A, derived from bisphenol A and epichlorohydrin. They are mostfrequently cured with anhydrides, aliphatic amines, or polyamides,depending on desired properties. Epoxy resins have been known to conveyoutstanding performance characteristics. However, variousmultifunctional resins, including epoxy cresol novolac resins (ECN) andpolynuclear phenol-glycidyl ether-derived resins have been developed tofurther improve high temperature performance and other selectproperties.

Epoxy resins have played a very important role in the advancement of theinformation industry. A variety of epoxy resins, especially the o-cresolepoxy novolac resins, for example, have been widely used for theencapsulation of semiconductor devices and as adhesives in themicroelectronic industry. Typically, liquid epoxy resins are synthesizedby a two-step process in which an excess of epichlorohydrin is reactedwith bisphenol A in the presence of at least a stoichiometric quantityof an alkaline catalyst, such as aqueous solutions of sodium hydroxide.The first step of the epoxy resin synthesis involves the formation of anintermediate, which is the dichlorodydrin of bisphenol A, and the secondstep involves a further reacion via dehydrohalogenation of theintermdeiate, again, with a stoichiometric quantity of alkali.

A number of improvements have been proposed in the prior art to improvethe epoxy resin synthesis process. In U.S. Pat. No. 5,028,686, it wasdisclosed a concurrent addition process for preparing high purity epoxyresins in which epoxy resins which are relatively low in total boundhalide are prepared by concurrently and continuously adding a mixture of(1) a mixture of an epihalohydrin, a compound containing an average ofmore than one group reactive with a vicinal epoxide group and a solventand (2) an aqueous or organic solution of an alkali or alkaline earthmetal hydroxide; to a mixture of epihalohydrin and a solvent.

U.S. Pat. No. 4,954,603 disclosed a process for making fire-retardantepoxy resins by reacting a trifunctional epoxy compound with halogenatedbisphenol A in the presence of a catalyst, which comprised sodiumhydroxide in a molar ratio of 2.85 to 1 relative to the trifunctionalepoxy compound.

European Patent 579301 disclosed a process for producing 4,4'-biphenolskeleton-containing epoxy resins, by reacting 4,4'-biphenol with aepihalohydrin in a reaction medium of glycol monoethers. During thereaction, an alkali metal hydroxide was gradually added to the reactionmixture. The total amount of alkali metal hydroxide added was between0.8 and 2.0 moles per mole of phenol groups.

European Patent 396203 disclosed an epoxy resin encapsulationcomposition comprising a tetrakisglycidyl ether of anα,α,ω,ω,-tetrakis(hydroxyphenyl)C₄ -C₁₄ alkane. The tetrakisglycidylether was produced by reacting an appropriate tetraphenol with ahalohydrin in the presence of an alkali metal hydroxide.

All the above mentioned patents involved, or at least claimed, certainimprovement over the conventional methods. However, all of them stillshare a common characteristic of the conventional methods in that allthe claimed processes still involved the addition of a strong base,which typically contained an alkali metal hydroxide in an aqueoussolution, or in a mixture of water and an alcohol solvent (such asisopropanol or butanediol, into the reaction mixture, which typicallycontained a polyphenol (bi-, tri-, or tetraphenol) and epihalohydrin.The amount of alkali metal hydroxide required is at least astoichiometric quantity of the phenol groups (i.e., every mole of phenolgroup would require at least one mole of alkali metal hydroxide in aone-to-one quantitative substitution reaction).

One of the disadvantages of the conventional processes in preparingepoxy resins is that, because the addition of the strong base of alkalimetal hydroxide is exothermic, it must be gradually added, as reportedin all the references mentioned above. Furthermore, the addition of thealkali metal hydroxide solution introduces water into an otherwiseorganic system. This causes the reaction to be conducted in anon-homogeneous multi-phase condition; and typically, it also requiresthe reaction to be conducted under an azeotropic condition. After thereaction, the removal of the high-boiling point water or alcohol alsoinvolves a tedious process; it requires a set of relatively complicatedpost-reaction equipment and is time-consuming. Thus, it is desirable todevelop alternative processes for making epoxy resins for use in themicroelectronic industry which involve simplified procedure and requirereduced reaction time.

SUMMARY OF THE INVENTION

The primary object of the present invention is to developpolyphenol-derived epoxy resins which can be advantageously used in themicroelectronic industry, and can be produced with a simplifiedprocedure that requires reduced reaction time. Alternatively, theprimary object of the present invention is to develop a simplifiedprocess for producing alternative epoxy resins, which would exhibit atleast the same excellent properties as currently available materials,for use in the microelectronic industry. The phenolepoxy resinsdeveloped in the present invention can be most advantageously used in ICpackaging, in making substrates for printed circuit boards, as adhesivesfor various electronic components, etc.

Unlike the conventional processes for making phenol-derived epoxy resinswhich require multiple reactants charging steps, the process disclosedin the present invention allows the raw materials of phenols andepihalohydrin to be added in the same step, along with the addition ofan imidazole catalyst. Furthermore, the process disclosed in the presentinvention does not require any solvent, and it involves substantiallysimplified manufacturing equipment, and incurs substantially reducedreaction time. Thus the cost of producing phenol-derived epoxy resinscan be substantially reduced. The process disclosed in the presentinvention is most advantageous with relatively large molecular weightepoxy resins wherein the starting reactants polyphenols have poorsolubility in epihalohydrin. The addition of the imidazole allowspolyphenol to be dissolved in the epihalogydrin so that the reaction canproceed in a homogeneous single phase, without the use of a aqueousbasic solution.

The advantages of the present invention involve not only thecost-effectiveness of the process for making epoxy resins, but also thesuperior properties of the phenolepoxy resins that are made therefrom.

The phenolepoxy resins disclosed in the present invention can berepresented by the following formula (I): ##STR2## where R¹, R², R³, andR⁴, which can be the same or different, are hydrogen, C₁ to C₆ alkylgroups, C₆ to C₁₀ aromatic groups, or C₁ to C₆ alkyl group-substitutedC₆ to C₁₀ aromatic groups; R⁵ and R⁶, which can be the same ordifferent, are hydrogen, C₁ to C₆ alkyl groups, C₆ to C₁₀ aromaticgroups, or C₁ to C₆ alkyl group-substituted C₆ to C₁₀ aromatic groups;##STR3## R⁷ is hydrogen, C₁ to C₆ alkyl groups, C₆ to C₁₀ aromaticgroups, or C₁ to C₆ alkyl group-substituted C₆ to C₁₀ aromatic groups;R⁸ and R⁹, which can be the same or different, are hydrogen, C₁ to C₆alkyl groups, C₆ to C₁₀ aromatic groups, or C₁ to C₆ alkylgroup-substituted C₆ to C₁₀ aromatic groups; and n is an integer of 0 or1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention discloses a family of new polyphenol-derived epoxyresins for use in the microelectronic industry which are produced with asimplified procedure requiring reduced reaction time relatively to theconventional processes. The phenolepoxy resins developed in the presentinvention can be most advantageously used, among other things, in ICpackaging, in making substrates for printed circuit boards, as adhesivesfor various electronic components, etc. One of the advantages of theprocess disclosed in the present invention is that, unlike theconventional processes for making phenol-derived epoxy resins, theprocess of the present invention allows the raw materials of phenols andepihalohydrin to be added in the same step, along with the addition ofan imidazole catalyst. Furthermore, the process disclosed in the presentinvention does not require any solvent, and it involves substantiallysimplified manufacturing equipment, and incurs substantially reducedreaction time. Thus the cost of producing phenol-derived epoxy resinscan be substantially reduced.

The phenolepoxy resins disclosed in the present invention can berepresented by the following formula (I): ##STR4## where R¹, R², R³, andR⁴, which can be the same or different, are hydrogen, C₁ to C₆ alkylgroups, C₆ to C₁₀ aromatic groups, or C₁ to C₆ alkyl group-substitutedC₆ to C₁₀ aromatic groups; R⁵ and R⁶, which can be the same ordifferent, are hydrogen, C₁ to C₆ alkyl groups, C₆ to C₁₀ aromaticgroups, or C₁ to C₆ alkyl group-substituted C₆ to C₁₀ aromatic groups;##STR5## R⁷ is hydrogen, C₁ to C₆ alkyl groups, C₆ to C₁₀ aromaticgroups, or C₁ to C₆ alkyl group-substituted C₆ to C₁₀ aromatic groups;R⁸ and R⁹, which can be the same or different, are hydrogen, C₁ to C₆alkyl groups, C₆ to C₁₀ aromatic groups, or C₁ to C₆ alkylgroup-substituted C₆ to C₁₀ aromatic groups; and n is an integer of 0 or1.

Preferably, R¹, R², R³, and R⁴, which can be the same of different, arehydrogen, C₁ to C₆ alkyl, C₁ to C₆ cycloalkyl, C₂ to C₆ alkenyl, C₂ toC₆ alkynyl, phenyl, naphthyl, or C₁ to C₆ alkyl-, C₁ to C₆ cycloalkyl-,C₂ to C₆ alkenyl-, C₂ to C₆ alkynyl-substituted phenyl or naphthylgroups; more preferably, R¹, R², R³, and R⁴ are hydrogen, methyl, ethyl,n-propyl, iso-propyl, n-butyl, iso-butyl, tert-butyl, pentyl, hexyl,phenyl, toluyl, or ethylphenyl groups, or even more preferably,hydrogen, methyl, tert-butyl, or phenyl groups.

Preferably, R⁵ and R⁶, which can be the same or different, are hydrogen,C₁ to C₆ alkyl, C₁ to C₆ cycloalkyl, C₂ to C₆ alkenyl, C₂ to C₆ alkynyl,phenyl, naphthyl, or C₁ to C₆ alkane-, C₁ to C₆ cycloalkyl-, C₂ to C₆alkenyl-, C₂ to C₆ alkynyl-substituted benzene or naphthalene groups,more preferably, R⁵ and R⁶ are hydrogen, methyl, ethyl, n-propyl,iso-propyl, n-butyl, iso-butyl, tert-butyl, n-pentyl, iso-pentyl,neo-hexyl, hexyl, phenyl, toluyl, or ethylphenyl groups, or even morepreferably, hydrogen, methyl, ethyl, n-propyl, or iso-propyl groups.

In Formula (I) shown above, the embodiments of R⁵ and R⁶ also include aradical represented by the following formula: ##STR6##

Preferably, R⁷ is hydrogen, C₁ to C₆ alkyl, C₁ to C₆ cycloalkyl, C₂ toC₆ alkenyl, C₂ to C₆ alkynyl, phenyl, naphthyl, or C₁ to C₆ alkyl-, C₁to C₆ cycloalkyl-, C₂ to C₆ alkenyl-, C₂ to C₆ alkynyl-substitutedphenyl groups, more preferably, R⁷ is a methyl, ethyl, n-propyl,iso-propyl, n-butyl, iso-butyl, tert-butyl, pentyl, hexyl, or phenylgroup.

The embodiments of R⁵ and R⁶ in Formula (I) also further include a grouprepresented by the following formula: ##STR7##

Preferably, R⁸ and R⁹, which can be the same or different, are hydrogen,C₁ to C₆ alkyl, C₁ to C₆ cycloalkyl, C₂ to C₆ alkenyl, C₂ to C₆ alkynyl,phenyl, naphthyl, or C₁ to C₆ alkyl-, C₁ to C₆ cycloalkyl-, C₂ to C₆alkenyl-, C₂ to C₆ alkynyl-substituted phenyl groups, more preferably,R⁸ and R⁹ are methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl,tert-butyl, pentyl, hexyl, phenyl, or toluyl groups.

Combining the above discussions, the preferred embodiments of R⁵ and R⁶in Formula (I) include hydrogen, methyl, ethyl, n-pentyl, iso-pentyl,and the following radicals: ##STR8## where Y is hydrogen or phenylgroup.

The phenolepoxy resins disclosed above are prepared by reactingpolyphenols with epihalohydrin in the presence of an imidazole catalyst.The polyphenols can be bi-, tri- or tetrapehnols, and alkyl or aromaticderivatives thereof. Preferably, the polyphenols are p, p' and o, o'polyphenols. During the reaction, the polyphenols are mixed withepihalohydrin and imidazole. The amount of imidazole should that itallows the polyphenols to be dissolved in epihalohydrin. Then thereaction mixture, which is in a homogeneous phase, is maintained at areaction temperature between about 90 and about 120° C. The reactiontime varies according to the substituted groups; typically, the reactiontime is about 1 to 4 hours. The epihalohydrin can be eitherepichlorohydrin or epibromohydrin; however, epichlorohydrin ispreferred. The amount of epihalohydrin should preferably between 1 and20 equivalents per every equivalent of phenol group, or more preferablybetween 1 and 5 equivalents of epihalohydrin per every equivalent ofphenol group. In the present invention, the imidazole catalyst isbroadly defined to include imidazole and its derivatives. A variety ofthe imidazole-type compounds can be used as catalysts in the presentinvention. Preferred examples of imidazole-type catalysts includeimidazole (1,3-diazole), 2-methylimidazole, 2-ethylimidazole,2-n-propylimidazole, 2-isopropylimidazole, and 2-phenylimidazole. Theamount of the imidazole catalyst should preferably between 0.01 and 0.5equivalents per equivalent of phenol group, or more preferably between0.01 and 0.2 equivalents per every equivalent of phenol group.

After the reaction, the reaction products can be added with 3 to 5 timesby volume of an organic solvent, such as methyl ethyl ketone,4-methyl-2-pentyl ketone, toluene, or mixtures thereof, and a 1Nhydroxide solution of approximately the same volume. After stirring andrefluxing for 1 to 4 hours, followed by extraction, drying,condensation, a raw product is obtained. The raw product so obtained canbe re-crystalized using an organic solvent such as methyl ethyl ketone,4-methyl-2-pentyl ketone, toluene, or ethanol, etc. The final productcan be further purified using column chromatography and othertechniques. The reaction yield can be as high as 85 to 95%.

The present invention will now be described more specifically withreference to the following examples. It is to be noted that thefollowing descriptions of examples, including the preferred embodimentof this invention, are presented herein for purposes of illustration anddescription, and are not intended to be exhaustive or to limit theinvention to the precise form disclosed.

EXAMPLE 1

Preparation of 4,4'-bis(glycidyloxy)-3,3'5,5'-tetramethylbiphenyl

48.4 g (0.20 mol) of 4,4'-dihydroxyl-3,3'5,5'-tetramethylbiphenyl, 0.68g (0.01 mol) of imidazole, and 185.2 g (2.0 mol) of epichlorohydrin wereinto a 500-ml reactor equipped with a mechanical stirrer and a coolingtube. The reactor was heated to 115° C. and the reactants were allowedto react under a reflux for two hours until the3,3'5,5'-tetramethyl-4,4'-dihydroxylbiphenyl was completely reacted (asindicated by column chromatography). The reaction products were cooledto room temperature, and the excess epichlorohydrin was removed by aspinning condensation device.

200 ml of 4-methyl-2-pentyl ketone and 50 ml of 1N sodium hydroxidesolution were added to the reaction product obtained above. The mixturewas heated to 90° C., stirred and reacted under a reflux for 2 hours.After being cooled down to room temperature, the organic layer and theaqueous layer were separated via an extraction procedure. The organiccontent in the aqueous layer was further extracted using4-methyl-2-pentyl ketone (160 ml, twice). The organic layers were thencombined, dried with sodium sulfate anhydrite, filtration, andspin-condensed, obtain a raw product.

The raw product was re-crystalized using 4-methyl-2-pentyl ketone. 60.4g of a white final solid product was obtained, indicating a reactionyield of 85%. The final product, which was4,4'-bis(glycidyloxy)-3,3'5,5'-tetramethylbiphenyl, is represented bythe following formula: ##STR9##

The melting point was measured to be 99.5-101.5° C., and the NMR resultsobtained on this product are summarized as follows:

¹ H NMR (CDCl₃, 200 MHz) δ 2.32 (12H, s), 2.72 (2H, dd, J=4.9, 2.7 Hz),2.88 (2H, dd, J=4.9, 4.4 Hz), 3.37 (2H, dddd, J=5.8, 4.4, 3.3, 2.7 Hz),3.42 (2H, dd, J=11.0, 5.9 Hz), 4.06 (2H, dd, J=11.0, 3.3 Hz), 7.15 (4H,s). ¹³ C NMR (CDCl₃, 100 MHz) δ 15.8 (q), 51.3 (t), 51.7 (d), 73.2 (t),128.2 (s), 130.9 (2C, d), 136.6 (2C, d), 154.8 (s).

EXAMPLE 2

Preparation of 4,4'-bis(glycidyloxy)biphenyl

The procedure in Example 2 was identical to that in Example 1, exceptthat 4,4'-dihydroxyldiphenyl was used instead of3,3'5,5'-tetramethyl-4,4'-dihydroxylbiphenyl, and that, during thepurification step, the reaction product was extracted using a mixture ofmethyl ethyl ketone and toluene, instead of the 4-methyl-2-pentyl ketoneused in Example 1. The raw product was further purified using methylethyl ketone to obtain a white solid product. The reaction yield wascalculated to be 95%.

The final product, which was 4,4'-bis(glycidyloxy)biphenyl, isrepresented by the following formula: ##STR10##

The melting point was measured to be 144-146° C., and the NMR resultsobtained on this product are summarized as follows:

¹ H NMR (CDCl₃, 200 MHz) δ 2.75 (2H, dd, J=4.9, 2.6 Hz), 2.90 (2H, dd,J=4.9, 4.3 Hz), 3.36 (2H, dddd, J=5.6, 4.3, 3.0, 2.6 Hz), 3.97 (2H, dd,J=11.1, 5.6 Hz), 4.24 (2H, dd, J=11.1, 3.0 Hz), 6.96 (4H, dd, J=8.7, 2.0Hz), 7.44 (4H, dd, J=8.7, 2.0 Hz).

EXAMPLE 3

Preparation of 2,2'-bis(glycidyloxy)biphenyl

The procedure in Example 3 was identical to that in Example 1, exceptthat, in addition to using a different polyphenol reactant (thepolyphenol reactant should correspond to the final product, since thisis well known in the art, this will not be elaborated), during thepurification step, the reaction product was extracted using toluene,instead of the 4-methyl-2-pentyl ketone used in Example 1. The rawproduct was further purified by silica gel to obtain a colorless liquidproduct. The reaction yield was calculated to be 92%.

The final product, which was 2,2'-bis(glycidyloxy)biphenyl, isrepresented by the following formula: ##STR11##

The NMR results obtained on this product are summarized as follows:

¹ H NMR (CDCl₃, 200 MHz) δ 2.54 (2H, dd, J=5.1, 2.5 Hz), 2.70 (2H, dd,J=5.1, 4.0 Hz), 3.16 (2H, dddd, J=5.5, 4.0, 2.9, 2.5 Hz), 3.93 (2H, dd,J=11.2, 5.5 Hz), 4.17 (2H, dd, J=11.2, 2.9 Hz), 6.95 (2H, dd, J=8.1,<1.0 Hz), 7.03 (2H, dd, J=7.3, 1.0 Hz), 7.24 (4H, m).

¹³ C NMR (CDCl₃, 100 MHz) δ 44.3 (t), 50.2 (d), 68.9 (t), 112.6 (d),121.0 (d), 128.3 (s), 128.5 (d), 131.4 (d), 155.9 (s).

EXAMPLES 4-7

The procedure in Examples 4-7 was identical to that in Example 1, exceptthat, during the purification step, the reaction product was extractedusing a mixture of methyl ethyl ketone and toluene, instead of the4-methyl-2-pentyl ketone used in Example 1. The raw product was furtherre-crystalized using toluene to obtain white solid products. Thereaction yields ranged from 85 to 90%.

Example 4

Preparation of 2,2'-bis (4-glycidyloxy-3,5-dimethyl)phenyl!propane

In Example 4, the reaction product,2,2'-bis(4-glycidyloxy-3,5-dimethyl)phenyl propane, is represented bythe following formula: ##STR12##

The NMR results obtained on this product are summarized as follows:

¹ H NMR (CDCl₃, 200 MHz) δ 1.56 (6H, s), 2.15 (12H, s), 2.69 (2H, dd,J=4.9, 2.6 Hz), 2.85 (2H, dd, J=4.9, 4.2 Hz), 3.33 (2H, dddd, J=5.9,4.2, 3.3, 2.6 Hz), 3.71 (2H, dd, J=11.0, 5.9 Hz), 4.00 (2H, dd, J=11.0,3.3 Hz), 6.80 (4H, s).

Example 5

Preparation of 1,1'-bis (4-glycidyloxy-3-phenyl)phenyl!propane

In Example 5, the reaction product, 1,1'-bis(4-glycidyloxy-3-phenyl)phenyl!propane, is represented by the followingformula: ##STR13##

The NMR results obtained on this product are summarized as follows:

¹ H NMR (CDCl₃, 400 MHz) δ 0.92 (3H, t, J=7.2 Hz), 2.06 (2H, dq, J=7.7,7.2 Hz), 2.64 (2H, dd, J=4.9, 2.6 Hz), 2.78 (2H, dd, J=4.9, 4.4 Hz),3.22 (2H, dddd, J=5.1, 4.4, 3.0, 2.6 Hz), 3.76 (1H, t, J=7.7 Hz), 3.93(2H, dd, J=11.1, 5.1 Hz), 4.15 (2H, dd, J=11.1, 3.0 Hz), 6.89 (2H, d,J=8.4 Hz), 7.15 (2H, dd, J=8.4, 2.2 Hz), 7.21 (2H, d, J=2.2 Hz), 7.30(2H, tt, J=7.3, 2.0 Hz), 7.39 (4H, t, J=7.3 Hz), 7.52 (4H, dd, J=7.3,2.0 Hz).

Example 6

Preparation of 1 1'-bis (4-glycidyloxy-3-phenyl)phenyl!butane

In Example 6, the reaction product, 1,1'-bis(4-glycidyloxy-3-phenyl)phenyl!butane, is represented by the followingformula: ##STR14##

The NMR results obtained on this product are summarized as follows:

¹ H NMR (CDCl₃, 200 MHz) δ 0.91 (3H, t, J=7.2 Hz), 1.27 (2H, tq, J=9.1,7.2 Hz), 1.99 (2H, td, J=9.1, 4.8 Hz), 2.63 (2H, dd, J=4.9, 2.5 Hz),2.76 (2H, dd, J=4.9, 4.4 Hz), 3.21 (2H, dddd, J=5.0, 4.4, 3.0, 2.5 Hz),3.68 (1H, t, J=4.8 Hz), 3.93 (2H, dd, J=11.1, 5.0 Hz), 4.14 (2H, dd,J=11.1, 3.0Hz), 6.87 (2H, d, J=8.3 Hz), 7.14 (2H, dd, J=8.3, 2.1 Hz),7.20 (2H, d, J=2.1 Hz), 7.35 (6H, m), 7.51 (4H, dd, J=7.1, 1.7 Hz).

Example 7

Preparation of 1,1'-bis (4-glycidyloxy-3-phenyl)phenyl!-2-methylpropane

In Example 7, the reaction product, 1,1'-bis(4-glycidyloxy-3-phenyl)phenyl!butane, is represented by the followingformula: ##STR15##

The NMR results obtained on this product are summarized as follows:

mp=131-134° C.

¹ H NMR (CDCl₃, 200 MHz) δ 0.83 (6H, d, J=6.5 Hz), 2.37 (1H, dsept,J=11.0, 6.5 Hz), 2.57 (2H, dd, J=4.9, 2.7 Hz), 2.71 (2H, dd, J=4.9, 4.4Hz), 3.15 (2H, dddd, J=5.0, 4.4, 3.0 2.7 Hz), 3.31 (1H, t, J=11.0 Hz),3.86 (2H, dd, J=11.1 5.0 Hz), 4.07 (2H, dd, J=1.1, 3.0 Hz), 6.81 (2H, d,J=8.2 Hz), 7.12 (2H, dd, J=8.2, 2.0 Hz), 7.20 (2H, d, J=2.0 Hz), 7.30(6H, m), 7.45 (4H, dd, J=6.9, 1.7 Hz).

EXAMPLE 8

Preparation of 2,2'-bis(4-glycidyloxy-3,3',5,5'-tetra-tert-butylbiphenyl

The procedure in Example 8 was identical to that in Example 1, exceptthat (in addition to the appropriate starting polyphenol), during thepurification step, the reaction product was recrystalized using ethanolto obtain a white solid product. The reaction yield was 85%. In Example8, the reaction product, 2,2'-bis(4-glycidyloxy-3,3',5,5'-tetra-tert-butylbiphenyl, is represented by thefollowing formula: ##STR16##

The NMR results obtained on this product are summarized as follows:mp=185-186° C.

¹ H NMR (CDCl₃, 200 MHz) δ 1.33 (18H, s), 1.43 (18H, s), 2.19 (2H, dd,J=4.9, 2.7 Hz), 2.63 (2H, dd, J=4.9, 4.4 Hz), 3.00 (2H, dddd, J=5.5,4.4, 3.3, 2.7 Hz), 3.57 (2H, dd, J=11.0 5.6 Hz), 3.68 (2H, dd, J=11.0,3.3 Hz), 7.14 (2H, d, J=2.4 Hz), 7.38 (2H, d, J=2.4 Hz).

MS (m/e): 522 (M⁺, base), 466 (base), 451, 337, 225, 57, 41, 29.

EXAMPLES 9-11

The procedure in Examples 9-11 was identical to that in Example 1,except that (in addition to the polyphenol reactants), the amounts ofepichlorohydrin and imidazole were increased to 1.5 times as much and,during the extraction step, the amount of sodium hydroxide solution wasalso increased to 1.5 times. The reaction product was extracted with4-methyl-2-pentyl ketone, and then concentrated to obtain whitesemi-solid products. The reaction yields ranged from 85 to 90%.

Example 9

Preparation of tris(4-glycidyloxyphenyl)methane

In Example 9, the reaction product, tris(4-glycidyloxyphenyl)methane, isrepresented by the following formula: ##STR17##

The NMR results obtained on this product are summarized as follows:

¹ H NMR (CDCl₃, 200 MHz) δ 2.72 (3H, dd, J=4.9, 2.7 Hz), 2.87 (3H, dd,J=4.9, 4.2 Hz), 3.31 (3H, dddd, J=5.5, 4.2, 3.1, 2.7 Hz), 3.92 (3H, dd,J=11.0, 5.5Hz), 4.16 (3H, dd, J=11.0, 3.1 Hz), 5.37 (1H, s), 6.81 (6H,dd, J=8.6, 2.5 Hz), 6.97 (6H, dd, J=8.6, 2.5 Hz).

Example 10

Preparation of bis(4-glycidyloxy-3-phenyl)phenyl!-(4-glycidyloxyphenyl)methane

In Example 10, the reaction product, bis(4-glycidyloxy-3-phenyl)phenyl!-(4-glycidyloxyphenyl)methane, isrepresented by the following formula: ##STR18##

The NMR results obtained on this product are summarized as follows:

¹ H NMR (CDCl₃, 200 MHz) δ 2.58 (2H, dd, J=4.9, 2.7 Hz), 2.66 (1H, dd,J=4.9, 2.6 Hz), 2.71 (2H, dd, J=4.9, 4.0 Hz), 2.81 (1H, dd, J=4.9, 4.2Hz), 3.16 (2H, dddd, J=5.0, 4.0, 3.0, 2.7 Hz), 3.25 (1H, dddd, J=5.5,4.2, 3.0, 2.6 Hz), 3.86 (1H, dd, J=11.1, 5.5 Hz), 3.87 (2H, dd, J=11.1,5.0 Hz), 4.10 (3H, dd, J=11.1, 3.0 Hz), 5.39 (1H, s), 6.76 (2H, d, J=8.9Hz), 6.81 (2H, d, J=8.4 Hz), 6.94 (2H, dd, J=8.4, 2.2 Hz), 6.99 (2H, d,J=8.9 Hz), 7.05 (2H, d, J=2.2 Hz), 7.25 (6H, m), 7.41 (4H, dd, J=6.9,2.0 Hz).

MS (m/e): 612 (M⁺, base), 539, 536, 463, 387, 298, 273, 197, 31.

Example 11

Preparation of 1- α-methyl-α-(4-glycidyloxyphenyl)ethyl!-4-α,α-bis(4-glycidyloxyphenyl)ethyl!benzene

In Example 11, the reaction product, 1-α-methyl-α-(4-glycidyloxyphenyl)ethyl!-4-α,α-bis(4-glycidyloxyphenyl)ethyl!benzene, is represented by thefollowing formula: ##STR19##

The NMR results obtained on this product are summarized as follows:

¹ H NMR (CDCl₃, 200 MHz) δ 1.57 (6H, s), 2.02 (3H, s), 2.67 (3H, dd,J=4.9, 2.5 Hz), 2.82 (3H, dd, J=4.9, 4.4 Hz), 3.26 (3H, dddd, J=5.4,4.4, 3.3, 2.5 Hz), 3.87 (3H, dd, J=11.0, 5.4 Hz), 4.11 (3H, dd, J=11.0,3.3 Hz), 6.72 (4H, d, J=8.8 Hz), 6.75 (2H, d, J=8.6 Hz), 6.86 (2H, d,J=8.8 Hz), 6.91 (4H, d, J=8.8 Hz), 7.01 (2H, d, J=8.6 Hz), 7.08 (2H, d,J=8.8 Hz).

EXAMPLES 12-13

The procedure in Examples 12-13 was identical to that in Example 1,except that, the amounts of epichlorohydrin and imidazole were increasedto twice as much and, during the extraction step, the amount of sodiumhydroxide solution was also doubled. After extraction and condensation,the reaction product was re-crystalized using 4-methyl-2-pentyl ketoneto obtain white solid products. The reaction yields ranged from 85 to87%.

Example 12

Preparation of 1,1'-2,2'-tetrakis(4-glycidyloxyphenyl)ethane

In Example 12, the reaction product,1,1'-2,2'-tetrakis(4-glycidyloxyphenyl)ethane, is represented by thefollowing formula: ##STR20##

The NMR results obtained on this product are summarized as follows:

¹ H NMR (CDCl₃, 200 MHz) δ 2.67 (4H, dd, J=4.9, 2.6 Hz), 2.83 (4H, dd,J=4.9, 4.4 Hz), 3.25 (4H, dddd, J=5.6, 4.4, 3.3, 2.6 Hz), 3.81 (4H, dd,J=11.0, 5.6 Hz), 4.06 (4H, dd, J=11.0, 3.3 Hz), 4.52 (2H, s), 6.64 (8H,d, J=8.5 Hz), 6.95 (8H, d, J=8.5 Hz).

MS (m/e): 622 (M⁺), 473, 347, 311 (base), 255, 136, 107, 57.

Example 13

Preparation of 1,1'-2,2'-tetrakis (4-glycidyloxy-3-phenyl)phenyl)!ethane

In Example 12, the reaction product, 1,1'-2,2'-tetrakis(4-glycidyloxy-3-phenyl)phenyl)!ethane, is represented by the followingformula: ##STR21##

The NMR results obtained on this product are summarized as follows:

¹ H NMR (CDCl₃, 200 MHz) δ 2.67 (4H, dd, J=4.9, 2.5 Hz), 2.82 (4H, dd,J=4.9, 4.4 Hz), 3.24 (4H, dddd, J=5.5, 4.4, 3.3, 2.5 Hz), 3.85 (4H, dd,J=11.1, 5.5 Hz), 4.08 (4H, dd, J=11.1, 3.3 Hz), 4.53 (2H, s), 6.80 (4H,d, J=8.2 Hz), 7.10 (4H, dd, J=8.2, 2.1 Hz), 7.20 (4H, d, J=2.1 Hz), 7.31(12H, m), 7.44 (8H, dd, J=7.0, 1.8 Hz).

For completeness of the this disclosure, the starting polyphenols forthe above examples are: 4,4'-bis(hydroxy)-3,3'5,5'-tetramethylbiphenyl;4,4'-bis(hydroxy)biphenyl; 2,2'-bis(hydroxy)biphenyl; 2,2'-bis(4-hydroxy-3,5-dimethyl)phenyl!propane; 1,1'-bis(4-hydroxy-3-phenyl)phenyl!propane; 1,1'-bis(4-hydroxy-3-phenyl)phenyl!butane; 1,1'-bis(4-hydroxy-3-phenyl)phenyl!-2-methylpropane; 2,2'-bis(4-hydroxy-3,3',5,5'-tetra-tert-butylbiphenyl;tris(4-hydroxyphenyl)methane; bis(4-hydroxy-3-phenyl)phenyl!-(4-hydroxyphenyl)-methane; 1-α-methyl-α-(4-hydroxyphenyl)ethyl!-4-α,α-bis(4-hydroxyphenyl)ethyl!benzene;1,1'-2,2'-tetrakis(4-hydroxyphenyl)ethane; and 1,1'-2,2'-tetrakis(4-hydroxy-3-phenyl)phenyl)!ethane, respectively.

The phenolepoxy resins prepared above exhibited low viscosity, excellentheat-resistance, and low moisture absorption, and thus are excellentmaterials to be used in IC packaging, encapsulation, making printedcircuit boards, and as adhesives in the electronics industry. Comparedto the conventional methods, the phenolepoxy resins of the presentinvention can be made in a process that involves a single feed-chargingstep, can be conducted in room pressure under reflux, and does notrequire any solvent. The process disclosed in the present invention forpreparing the phenolepoxy resins also provides many other advantagesrelative to the conventional process in that it requires simplifiedproduction facility, involves much simplified procedure, incurs reducedreaction time, and provides high production yields.

The foregoing description of the preferred embodiments of this inventionhas been presented for purposes of illustration and description. Obviousmodifications or variations are possible in light of the above teaching.The embodiments were chosen and described to provide the bestillustration of the principles of this invention and its practicalapplication to thereby enable those skilled in the art to utilize theinvention in various embodiments and with various modifications as aresuited to the particular use contemplated. All such modifications andvariations are within the scope of the present invention as determinedby the appended claims when interpreted in accordance with the breadthto which they are fairly, legally, and equitably entitled.

What is claimed is:
 1. A phenolepoxy resin prepared by reacting apolyphenol, epihalohydrin and an imidazole in a homogenous reactionmedium, and selected from the group consisting of ##STR22##
 2. Thephenolepoxy resin according to claim 1 wherein said phenolepoxy resinis:
 3. The phenolepoxy resin according to claim 1 wherein saidphenolepoxy resin is:
 4. The phenolepoxy resin according to claim 1wherein said phenolepoxy resin is:
 5. The phenolepoxy resin according toclaim 1 wherein said phenolepoxy resin is:
 6. The phenolepoxy resinaccording to claim 1 wherein said phenolepoxy resin is:
 7. Thephenolepoxy resin according to claim 1 wherein said phenolepoxy resinis:
 8. The phenolepoxy resin according to claim 1 wherein saidphenolepoxy resin is:
 9. The phenolepoxy resin according to claim 1wherein said polyphenol and said epihalohydrin do not form a homogeneoussolution in the absence of said imidazole.
 10. The phenolepoxy resinaccording to claim 1 wherein said imidazole is added in such an amountso as to allow said polyphenol and said epihalohydrin to form ahomogeneous phase.
 11. A phenolepoxy resin which is selected from thegroup consisting of the following compounds:
 12. The phenolepoxy resinaccording to claim 11 which is prepared by an aqueous-phase-freeprocess.
 13. The phenolepoxy resin according to claim 11 which isprepared by reacting polyphenol, epihalohydrin and imidazole in ahomogeneous reaction medium free of an aqueous phase.